Apparatus for setting up corner lock cartons



June 28, 1960 w. .e. ATKINSON 2,942,533

APPARATUS FOR SETTING u comma LOCK CARTONS Filed Nov. 19,1956

ZSheets-Sheet 1 y A l L INVENTOR' FIG. 3 WILLIAM G. ATKINSON ATTORNEYS June 28, 1960 w. e. ATKINSON APPARATUS FOR SETTING up CORNER LOCK cARToNs Filed Nov. 19, 1956 2 Sheets-Sheet 2 v NTOR LL/AM a. ATKINSON ATTORNEYS 3% gig APPARATUS FOR SE'I'IIING UP CORNER LOCK CARTONS William Gerald Atkinson, London, Ontario, Canada, assignor to Somerville Limited, London, Ontario, Canada Filed Nov. 19, 1956, Ser. No. 623,035

2 Claims. (CI. 93-51) This invention relates to apparatus for setting up corner lock cartons. v

Corner lock car-tons have been used to a considerable extent but are sometimes disadvantageous in the case where they do not provide for a positive lock. A number of constructions employing tabs and slots will tend to secure the corner but inmany cases will release afterwards when put into use. 2,809,776 of October 15, 1957, there is disclosed a corner lock carton whereinthe tabs which fit into slots in the wall of the carton to achieve the lock are designed to include a portion which will overlap the slot on the inatent with the area of the base 11 (see Fig. 7) of the carton blank which is to be set up by the apparatus. 7

The carton'blank comprises in addition to the base 11 the opposed pairs of sidewalls 12 and 13 and 14 and 15 respectively swingably connected with the base. The side walls 14 and 15 are formed with spaced apartparallel slits 15 which are designed to receive the securing tabs 17 of the end flaps 18 which are formed co-extensive with the side walls 12 and 13 and foldable along transverse crease lines so that they are disposed in juxtaposition to the side walls 14and 15 respectively when the carton is being folded to set-up position. When the flaps are folded in juxtaposition with theside walls 14 and 15 the tabs 17 are designed to pass through the slits 16 in such walls to dispose the tabs therewithin and then the locking tongues 19 are designed to be flexed over one'edge of the slits 16 to overlap the interior surface of side walls 14 and 15 to one side of the slits 16 as, for

instance, shown in Fig. 6 so that the carton is firmly In United States Patent No.

terior of the canton, thus to provide a very positive lock;

The apparatus of the present invention constitutes a comparatively simple and positive means for causing the tabs of such carton and similar cartons to overlap, on

the inside of the carton, edges of the slots into which 1 they are projected after the tabs have been caused to enter the slots. V

' The invention generally comprises a female die and a plunger cooperatively related to en-gage a blank disposed therebetween and to fold the blank into set-up carton formation including a means for causing the tabs of certain side walls of the carton to enter into slots of the other walls of the carton, including means for causing the slots pantially to open preliminarily to the introduction of the tab thereto and a means of pressing the tabs and slotted walls of the carton inwardly to cause a portion of the tab to overlap the slot-on the interior of the carton.

The invention will be clearly understood by reference to the following detailed specification taken in conjunction with the accompanying drawings.

In the drawings:

Fig. 1 is a top plan view of the female die illustrat ing the die plunger disposed in the die opening.

Fig. 2 is a longitudinal section taken on the line 2-2 of Fig. 1 I

Fig. 3 is a viewsomewhat similar to Fig.2 but illustrating the die plunger in its lowermost position after pressing a carton blank through the die to illustrate the manner in which the carton is stripped from the die.

Fig. 4 is a schematic end elevation of a carton shown in relation to one 'end of the die through which'itis caused to pass. I

Fig. 5 is an enlarged fragmentary sectional detail of one end of the carton to show the manner in which the locking tabs are introduced to the slots and one of the carton walls.

Fig. 6 is a fragmentary perspective detail showing the interior of one end of the canton and the position of the tabs when locked; and

Fig. 7 is a plan view of the carton blank.

Referring to the drawings, A indicates a die formed with a central die opening 10 through which a plunger B is designed to pass in cooperative association. The opening 10 and die plunger B are of generally rectangular outline of correlated size and substantially coincide locked in the set-up position. The apparatus is so constructed as to perform these functions in a simple and positive manner.

The die A is provided with a table-like portion 20 upon which the carton blank is disposed in such a manner that the base thereof 11 overlies the opening 10 and which may be accomplished by providing a suitable stop member 21 on the upper surface of the die to one side of the'opening 10 against which one edge of the carton may be caused to engage. The base of the blank 11 is,

therefore, aligned with the right angular corners 22' of the die opening and the table portion thereofis prefer'a bly. sloped inwardly and downwardly as at 23 to permit the side walls 12 and 13 of the blank readily to fold along their crease lines as the base of the blank is pressed downwardly into thedie opening 10 by .the die I plunger B.

The opposite side walls of the die opening 10 are formed with the inwardly projecting parallel spaced apart bosses 24 which are spaced apart a distance coinciding with the width of portion 16a between the slits, 16 on each of the side walls 14 and 15 of the blank, for the purpose of causing said slits to open to an extentsuf ficiently readily to receive the securing tabs 17 during the folding operation and which will be explained. more fully hereinaiter. Suitably rounded or tapered surfaces 25 [are provided adjacent each end of the die opening in the upper surface of the die whereas the upper edge 'of the bosses 24 are also preferably rounded in the direction towards the die openingso that the [flaps 18 and the side walls 14and 15 which overlie that portion of the die will tend readily to fold inwardly as thedie plunger B presses the base of the blank downwardly into the die opening, similarly to the function of the sloped surfaces 23 along the other sides of the dieopening in respect to the folding of the side walls 12 and 13.

At each end of the die A beyond the opening 10, retaining ledges 26 are provided with are clearly illustrated in Figs. 2 and 3. They may take the form of plates secured to a raised :base structure 27 disposed 'on the upper surface of the die and are preferably provided with upwardly curved end guide surfaces 28 (Figs. 2 and 3 so that whenthe blanks are fed to the die inthe direc-@ tion of the arrow '29 (Fig. 1), the side walls 14 and 15 will be guided under the ledges 26. In the first instance,

bearing engagement between the bosses 24 and the por-' tions 16b of end walls .14 and 15 cause portions 16b of the end walls 14 and .15 to bell inwardly, thus opening slits 16. Moreover, the recess 30 in effect tormed along the ends of the die opening between the bosses 24 has the effect of receiving portion 16a of the end walls 14 and 15, whereas the bosses 24 tend to maintain the inward belling of the remaining portion 16b of said walls tomaintain the'open slits. Consequently, as the blank is pressed by thedie downinto the opening .10 and the walls .12 and 13 fold inwardly while the flaps 18 swing into juxtaposition with the end walls, the securing tabs 17 thereof will automatically. move into the open slits 16.

As may benoted from Fig. 4 where the seeming tabs 17 are illustrated'in dottedlines disposed in the set-up position, the locking tongues '19..are disposed to overlap the axial line of the slits 16 and when the tabs 17 are moved into the open slits 16, the locking tongues 19 will normally be disposed on the outside of the Walls .14.and 15 but must .hepassed through the slits to overlap the axial line thereof .on the .inside.for locking purposes. To accomplishthis the die plunger B isiformed at each end with the spaced apart recesses 31 which as shown indotted lines in Fig. 4 are disposed slightly to overlap the axial line of the slits 16 in side walls 14 and '15 of the carton blank when such walls are swung in parallel relation to the die plunger B in the folding operation. Moreover, as shown particularly in Figs. 2 and 3 and in dotted line illustration in Fig. 4, a means is provided for engaging the securing tabs 17 and pressing them and the portion 16:: of side walls 14 and 15 slightly inwardly, which has the effect of flexing the tongues 19 inwardly through the slits to dispose them in overlapping relation thereto on the inside of the container as shown in Fig. 6.

A preferred form of such tab engaging means is illustrated and which takes the form of rollers 32 each rotatably mounted on one arm of the hell crank levers .33 pivoted as at 34 on the die framework, the opposite arms of the bell crank levers being spring pressed by the coil springs 35 mounted on suitable belts or rods passing through slotted portions of the latter arms of the bell crank levers 33. Thishas the effect of normally disposing the rollers inwardly in relation to the die opening 10 and partially in'the path of the die plunger B.

As illustrated in Fig. 1, there are two rollers 32 in spaced relationship to one another at each end of the die opening and which are positioned to align with the slits '16 of the side walls 14 and 15 of the carton blank when his caused to fold and move in through the die opening 10. Preferably these rollers are formed with a centrally located annual contact head 36 which is disposed in each case to engage the walls 14 and 15 of the blank just inwardly of the slits 16. In result, therefore, when the die plunger B carries the folded carton down through the die opening 10 at which time the carton has been folded and thesecuring tabs 17 have been passed into the open slits 16, the pressure of the annular head on walls 14 and 15 just inwardly of the slits 16 will cause the portion of these walls between the slits to flex inwardly into the recesses 31 in the die plunger B and automatically, therefore, flex the locking tongues 19 past the edge of slits 16 which they lap and will then cause them to lap such .edge on the inside of the folded carton. flaps 18 of the side walls 12 and 13 are securely locked to the side walls 14 and 15 in the manner shown in Fig. 6.

As the locking tongues 19 of the flaps 18 are locked in the manner described when the die plunger B passes down through the die opening 10, the plunger continues in its travel until it reaches the position approximately as shown in Fig.3 so that the carton is free of the die opening and parts of the side walls 14 and 15 will tend tofflex outwardly when .freed, viz., the foldable end .flaps 37 Consequently, the

substantially as illustrated. It will be also noted that the die A is'provided with a pair of strip metal cross bars 38 mounted on depending brackets 39 rigidly carried by the die framework A. Consequently these outwardly flexed portions of the carton will become disposed below the bars 38 which will function as carton stripping means as the die-plunger 3 moves back.in a returnmovement. In this way at thispoint the set-up carton is "readily stripped from the die and'the 'dieis returned to the initial position forsoperating .upon the "next blank :fed .to:the die.

Gfcoursegthe blanks :rnay beffed inanysuitable way such as by hand or by any suitable mechanism and it will be clear thatin-a quick operating cycle theblank is folded into set-up position, the securing "ilaps '18 thereof projected into the openedslits '*16.of .theopposed walls, the locking tongues are flexed and locked inside these walls, and the set-up carton stripped from the die. This is all accomplished by very simple, quick acting, positive mechanism as above described which is associated with any suitable ,power set-up for causing the parts to coact efficiently in sequence of operation as described.

.I claim:

1. Apparatusifor setting'up carton blanks having a pair of opposed slit-walls and designed to receive securing flaps of an opposed pair-of walls to set up the carton, wherein portions of said flaps overlap the axial line of said receiving slits on the outside of said carton and are projected to overlap-said axial line inside said carton as the carton'is set up, comprising a die having a die opening designed substantially to fit the perimeter of the carton, a die plunger capable of passage through said die .opening and of engaging the base of a carton blank disposed over said opening, means in connection with saiddie for causing the wallsof the carton blank to-fold into juxtaposed position as the die plunger moves the base of the blank through the die opening, means mounted on the die at opposite ends of the die opening and spaced above the plane of said opening-for engaging the outer end edge portions of said slit wallspreliminarily toretard movement thereof towards set opposition 'for freeing, portions of the end flaps along theilines of said slits, complementary means on the die cavity wall and-on the end of the plunger for flexing said freed portion of said wall between said slits ontwardly and out of alignment withthe otherportions of said will, whereby to open said slits partially to receive .the securing flaps, and roller means mounted adjacent to the die opening for engaging said slit walls inwardly of and adjacent to said slits for causing portions of said flaps notreceived by said s'lits, and which overlap the slits on the outside of the carton, to llex and move inwardly through the slits to overlap the axial line thereof on the inside of the carton.

2. Apparatus for setting up carton blanks as claimed in claim lin which said roller means includes a peripheral bead engageable with said slit walls inwardly of said slits and resilient means for causing said roller means iyieldingly to-engage said walls.

References Cited in the'file 'ofthis patent UNITED STATES PATENTS 1,906,283 Schulz -1. May 2, 1933 2,553,733 Acker May 22, 1951 2,604,827 Hick-in-et al July 29, 1952 2,608,916 *Hickin Sept. 2, 1952 2,627,791 Ringler Feb. 10,1953 2,743,651 Wilcox 'May 1,1956 "2,819,660 Johnson Jan. 14, 1958 

